• Korean Journal of Weed Science
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• v.11 no.1
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• pp.11-18
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• 1991

Seven formulations of oxyfluorfen selected from the previous studies(4. 5) were tesed to evaluate crop injury and herbicidal efficacy on two rice cultivars and several annual and perennial weeds in a greenhouse. Each formulation at two different rates was applied to rice transplanted with 8-, 22- and 32-day old seedlings and to direct-seeded rice. Among the formulations, Elvan, Bentonite B. Chitosan and Coal Slag gave lower injury than a control formulation, Sand-coated oxyluorfen, and they did not have a problem with excessive release if active ingredient at once. Especially, the formulations of Elvan, Chitosan and Bentonite B controlled annual weeds (Echinochloa crus-galli, Monochoria vaginalis, Cyperus difformis., and Scirpus juncoides) and perennial weeds (Sagittaria pygmaea, and Cyperus serotinus). The surface structure of the formulations indicate the different possibilities of releasing of oxyfluorfen by different cracking and hole sizes, namely retention capacity.

• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.82-86
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• 1983

Cone and seed development after self-pollination in 14-year-old Pinus rigida Mill. was investigated in an $F_1$-hybrid seed orchard that consists of Pinus rigida Mill. and Pinus taeda L. in alternative rows. On an average, 83.8% of the self-pollinated receptive female strobili developed into cones. This value appears to be normal compared to cone development after open-pollination in other pine species such as in Pinus sylvestris L. However, there was a great variation in filled seed development after self-pollination among the investigated individual trees (Table 1-1). The 34.5%, a ratio of filled seeds after self-pollination was significantly lower than 91.7%, that by the open-pollination. Some of the investigated trees developed 70.0%-83.5% of filled seeds after self-pollination. Thus, those are not desirable as trees for seed parent in establishing $F_1$-hybrid seed orchards in future. A further study on the rate of filled seed development by various pollination systems consisting of self-pollination, self-and cross-pollination with intraspecific, mixed (tree's own and foreign pollens) pollens and cross-pollination with interspecific, mixed pollens of the two parental tree species is necessary to determine the quality of seed parent trees in establishing $F_1$-hybrid seed orchards.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.3
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• pp.109-114
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• 2011

A breeding population of Quercus glauca has been established via simple direct selection. Seedlings from naturally crossed seeds of 35 selected families growing in Jeju Island were placed using stroll repeated planting into two experimental forest located at Hannam and Sanghyo in Jeju. After 3 years of planting, characteristics of growth were examined. Growth pattern of trees in Sanghyo was better than those in Hannam. The average heights of filial were 66.8 cm in Hannam and 92.5 cm in Sanghyo. Root collar diameters of filial in Hannam and Sanghyo were 9.3 mm and 12.2 mm, respectively. A great weather differences especially in precipitation and temperature were shown between two test sites. The result of difference of growth pattern between two sites could be useful in provenance adaptability test. Data within families and individuals obtained from this study was also useful for establishment of seed orchard of Q. glauca.

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.71-78
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• 2024

This study was in order to select soybean (Glycine max (L.) Merrill) cultivars that are suitable for cultivating in paddy fields of the southern Korea and beneficial for mechanized harvesting with combine harvesters. Five soybean cultivars were cultivated in paddy fields to survey growth characteristics and seed yield, and evaluate the nutritional value of seed. Plant height was longer than 55 cm for 'Cheongja-3ho', 'Daewon' and 'Seonpung'. First pod height was higher than 12 cm for 'Daewon', 'Seonpung', and 'Seonyu-2ho'. Seed yields were 280 kg/10a or more for 'Daechan', 'Seonpung' and 'Daewon'. The protein content of 'Daechan' were 40.7%, which was significantly higher than those of the other cultivars, and isoflavone content was higher than 200 ㎍·g^-1 for 'Seonpung', 'Cheongja-3ho', 'Daechan', and 'Daewon'. These results suggest that 'Daechan', 'Seonpung', 'Daewon' could be suitable for cultivating in paddy fields, and 'Daewon' and 'Seonpung' could be more beneficial for mechanized harvesting with combine harvesters. Furthermore, 'Daechan' and 'Seonpung' have not only high seed yields, but also high protein and isoflavone contents, suggesting that they could be used for production of various food products.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.463-469
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• 2000

Douglas-fir (Pseudotsuga menziesd Mirb. Franco) is highly regarded as a commercial timber species throughout the world in part due to its fast growth relative to many other species. In this study, basal area per hectare equation for Douglas-fir plantations in Southland of New Zealand has been developed based on medium measurement cycles of permanent sample plots data set. The function was developed using the algebraic difference equation method, and various sigmoid-shaped projection equations were used. Parameter estimation was obtained by non-linear routine of the SAS. As a result, of the functions tested a variant of the Schumacher polymorphic function including site index and thinning term as predictor variables showed the higher precision of the fitting. The results indicate that site index is positively correlated with basal area growth. And the thinning term was found to be useful to increase precision of the model.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.159-166
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• 1991

Seven oxyfluorfen formulations were tested for control of 8 weed species and rice injury under four different water depths with various ages of rice seedlings. Among formulations tested, rice injury was slight by formulations of Elvan, Coal Slag, Chitosan and Bentonite B under 0 cm or shallow water depths, and by those of Elvan and Coal Slag under deep water conditions. Weed control was high by Bentonite A and B, and Chitosan, and was low by Elvan. Coal Slag and Sand coated oxyfluorfen, if the target weeds of oxyfluorfen are annual species, further development of Elvan, coal slag, chitosan and Bentonite A would be controlled to increase control efficacy or to decrease rice injury.

• The Korean Journal of Ecology
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• v.26 no.6
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• pp.341-347
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• 2003

Historical Documents on Proper Tree Selection System of Korea were collected in Japan and introduced in this review. Products of some pine species and fruit were used for laying a tribute to Kings in the Chosun dynasty. In this review, some case studies and implementation of proper tree selection system during the period of Japanese rule, the atlas of climatically favourable regions for the species of trees and bamboos in Korean peninsular, and the test results on regional afforestation, tree selection and proper tree selection of fast growing trees were introduced. Of these documents, especially, the atlas of climatically favourable regions of trees and bamboos growing in Korean peninsular is considered as a valuable document. It tis expected that these historical documents on proper tree selection system might be use as references for the researches on indigenous forest, forest resources development, afforestation of fire damaged areas, and the restoration project of North Korea by the time of reunification of Korea.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.289-294
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• 2009

Concerning about the negative impact of chemical pesticides on human health and the environment has been leading to dramatic increase of research in natural product-based pesticides. An antagonistic bacterium Streptomyces sp. S-1110 was isolated from apple farm soil. The culture filtrate of the strain showed growth inhibition effects to apple pathogenic fungi, Botryosphaeria dothidea, Colletotrichum gloeosporioides and Rhizoctonia solani. The unidentified antibiotic substances from the strain kept antagonistic activity either after heat treatment at $121^{\circ}C$ for 1 h or pH treatment at range of pH 3 - pH 12 for 24 h. The substances also prevented apple fruit from spoiling by inoculated two pathogenic molds, B. dothidea and C. gloeosporioides. These results suggested that the isolated strain would be useful as a biocontrol agent to control apple spoiling occurred from mold.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.189-195
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• 2006

We investigated the genetic variation in Stewartia koreana Nakai by examining 61 I-SSR amplicons in 120 individuals distributed among six natural populations in Korea. The overall percentage of polymorphic I-SSR amplicons was 81.9% and mean number of amplicons per I-SSR primer was 12.2. Levels of genetic diversity within 6 populations were similar each other[Shannon's Index $0.358{\sim}0.467$(mean: 0.407)]. The Mt. Obong population had the highest level of genetic diversity and was most distinctive from the other populations. Most variation existed among individuals within population(88.2%). Genetic differentiation among populations(${\phi}_{ST}$) was 0.118. The UPGMA dendrogram based on the genetic distance failed in showing decisive geographic relationships.

• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.1-10
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• 1979

This study was conducted to widen the range of characteristics of the hybrids, P.alba ${\times}$ P.glandulosa, i.e. aiming for gene population expansion P.glandulosa seemed to have the similar characteristics as the one segregated from the natural hybrids between P.alba and P.davidiana. Thus the main objectives of this study were to make many crosses among poplars and then to identify leaf characteristics of the crosses similar to P.glandulosa, the results obtained can be summerized as follows; 1. Leaf characteristics such as leaf margin, presence of glands at leaf base and pubescence density, of crosses made from P.alba.davidiana ${\times}$ P.datidiana, and P.davidiana.alba ${\times}$ P.davidina showed 44% and 90%, respectively, of similarity to P.glandulosa. 2. The ratio of leaf size, including leaf length, leaf width, length from leaf base to width line, and petiole length, of the above crosses was similar to P.glandulosa. 3. Pubescence density of the dorsal leaf surface in hybrids between P.alba and P.davidiana showed generally intermediate of the parental appearance. Frequency of pubescence appearance differed from depending upon the use of P.alba, either as a female or a male parent. The use of P.alba as a male parent increased frequency of Pubescence appearance. 4. The presence of glands at the leaf base in P.glandulosa may be inherited from P.davidiana which possesses gland although gland is not present in all P.davidiana rather from P.alba which has no gland.